The Sensitivity of Differential Ratings of Perceived Exertion as Measures of Internal Load.

PURPOSE To investigate the sensitivity of differential ratings of perceived exertion (dRPE) as measures of internal load. METHODS Twenty-two male university soccer players performed 2 maximal incremental-exercise protocols (cycle, treadmill) on separate days. Maximal oxygen uptake (VO2max), maximal heart rate (HRmax), peak blood lactate concentration (B[La]peak), and the preprotocol-to-postprotocol change in countermovement-jump height (ΔCMJH) were measured for each protocol. Players provided dRPE (CR100) for breathlessness (RPE-B) and leg-muscle exertion (RPE-L) immediately on exercise termination (RPE-B0, RPE-L0) and 30 min postexercise (RPE-B30, RPE-L30). Data were analyzed using magnitude-based inferences. RESULTS There were clear between-protocols differences for VO2max (cycle 46.5 ± 6.3 vs treadmill 51.0 ± 5.1 mL · kg-1 · min-1, mean difference -9.2%; ±90% confidence limits 3.7%), HRmax (184.7 ± 12.7 vs 196.7 ± 7.8 beats/min, -6.0%; ±1.7%), B[La]peak (9.7 ± 2.1 vs 8.5 ± 2.0 mmol/L, 15%; ± 10%), and ΔCMJH (-7.1 ± 4.2 vs 0.6 ± 3.6 cm, -23.2%; ± 5.4%). Clear between-protocols differences were recorded for RPE-B0 (78.0 ± 11.7 vs 94.7 ± 9.5 AU, -18.1%; ± 4.5%), RPE-L0 (92.6 ± 9.7 vs 81.3 ± 14.1 AU, 15.3%; ± 7.6%), RPE-B30 (70 ± 11 vs 82 ± 13 AU, -13.8%; ± 7.3%), and RPE-L30 (86 ± 12 vs 65 ± 19 AU, 37%; ±17%). A substantial timing effect was observed for dRPE, with moderate to large reductions in all scores 30 min postexercise compared with scores collected on exercise termination. CONCLUSION dRPE enhance the precision of internal-load measurement and therefore represent a worthwhile addition to training-load-monitoring procedures.